How to view data from lookup fileset

singhald · Post by **singhald** » Mon Feb 22, 2010 5:49 am

Hi ,

do we have any utility to view data from LookupFileSet stage.

thanks

ArndW · Post by **ArndW** » Mon Feb 22, 2010 6:35 am

No such utility exists; this is the major drawback of using a looup fileset and some tests that I did at V7 showed that the performance gains of a lookup fileset versus a dataset were not particularly great. For this reason I don't use them anymore.

abhijain · Post by **abhijain** » Mon Feb 22, 2010 7:35 am

You can not view data of lookup fileset. No such utility exist.

ray.wurlod · Post by **ray.wurlod** » Mon Feb 22, 2010 3:51 pm

Data are stored in a Lookup File Set in a pre-indexed format. Because of this the only access method is "read by key", which the data browser does not support.

The benefit is that, when used with a Lookup stage, the LUT_CreateOp operator does not need to be executed because the index already exists in the Lookup File Set - it can simply be moved into memory rather than built "on the fly". This is particularly beneficial when many jobs use the same reference data, particularly if there are many rows. Of course, the reference data still have to fit into memory, into a virtual Data Set.